This invention relates generally to audible and ultrasound inspection of objects, including living patients.
Auscultation is a common method used by general practitioners to diagnose heart or lung disease. Auscultation requires a conventional, electronic or digital stethoscope. A conventional acoustic stethoscope uses an air cavity (e.g., a Helmholtz resonator) coupled to a duct, which itself is inserted into an ear. Known electronic stethoscopes passively pick up ultrasound signals using a microphone and then use electronic amplifiers and filters to electronically enhance the signals. Digital stethoscopes are electronic stethoscopes with the capability of storing the sound digitally and transferring the sound to a computer for analysis.
More recently, ultrasound echoes have been used by specialists to confirm or reject some findings from auscultation. It has been shown that simultaneous auscultation and echo adds value to certain diagnostic examinations.
Portable ultrasound machines are known and are used in much the same way as larger ultrasound scanners. However, ultrasound imaging devices that fit in the palm of one's hand are currently under development. These palm-top devices have the potential to become visual “stethoscopes” that can complement auscultation during a physical exam. (See, for example, Xie T, Chamoun A J, McCulloch M, Tsiouris N, Birnbaum Y, Ahmad M., “Rapid screening of cardiac patients with a miniaturized hand-held ultrasound imager—comparisons with physical examination and conventional two-dimensional echocardiography,” Clin Cardiol. 2004 Apr.;27/4:241-5, Duvall W L, Croft L B, Goldman M E, “Can hand-carried ultrasound devices be extended for use by the noncardiology medical community?” Echocardiography. 2003 Jul.;20/5:471-6, and Kotler M N, Segal B L, Parry W R, “Echocardiographic and phonocardiographic correlation of heart sounds and murmurs,” Cardiovasc Clin. 1978;9/2:39-57.) However, with presently known palm-top devices, it still requires at least two persons or at least an exceptionally experienced user to perform echo and auscultation examinations simultaneously.
Performing auscultation and echo simultaneously requires two separate devices, either in form of a stethoscope and an echo machine or two separate probes connected to one ultrasound scanner (e.g., separate ultrasound and phono probes).
Moreover, while visual ultrasound stethoscopes may be superior to ordinary stethoscopes in detecting cardiac disease or in other diagnostic applications, a visual ultrasound stethoscope cannot completely replace an ordinary stethoscope because ultrasound signals do not penetrate air-filled organs like the lung and intestines. Thus, for example, when a physician is doing ward rounds with a hand-held scanner, he still needs to carry an acoustic stethoscope.